The present invention relates to a device for the disconnectable coupling of a support toggle or knuckle joint of a gripping member to the end of a slave arm of a remote manipulator, as well as to a disconnection support for receiving the toggle or knuckle joint and its gripping member, in order to automatically ensure the remote connection and disconnection of the coupling device connecting the toggle or knuckle joint to the slave arm.
In order to carry out manipulations within a cell having to be insulated from the external atmosphere, particularly because the medium contained in the cell is a toxic or dangerous medium such as a radioactive medium, it is conventional practice to use various remote manipulation or handling means, which include so-called masterslave manipulators. These manipulators comprise, outside the cell, an articulated and/or telescopic master arm carrying a control handle at its end and, within the cell, a slave arm which is identical or similar to the master arm and carries at its end, via a toggle joint, a gripping member usually constituted by a claw.
In such remote manipulators, mechanical or electrical means are provided so that an identical or similar movement of the slave arm corresponds to any movement carried out on the master arm by an operator. Moreover, the control handle is equipped with an actuating member such as a trigger making it possible to control, via mechanical or electrical means, the closing of the gripping claw or gripper, whilst its opening can be controlled in the same way, or can be carried out automatically with the aid of elastic means incorporated into the gripper.
For example, the transmission of different movements between the master arm and the slave arm can be carried out in particular by means of straps or cables winding onto pulleys and whose displacements are controlled by capstans.
It is clear that master-slave manipulators constitute complex mechanisms periodically requiring interventions, in order to change certain parts. When the parts are on the side of the master arm, no special problem is linked therewith. However, any intervention which has to be carried out in connection with the slave arm involves a very precise process made necessary by the need to preserve the confinement of the cell and by the contamination of certain parts when working in a radioactive atmosphere. In order to take account of the latter requirement, the slave arm is generally disposed within a protective sleeve limiting its contamination, whereas the toggle joint and gripper are placed within the enclosure without any protection.
Consideration has been given to the separation of the toggle joint - gripper assembly from the reset of the slave arm in order to give a different treatment in connection with the highly contaminated parts (toggle joints and gripper) as compared with that required for the slightly contaminated parts (segments of the slave arm). Thus, when the intervention is to take place on the toggle joint or gripper, the disconnection of this relatively small assembly makes it possible to transport it in a lead transporting casket to an appropriate intervention cell, where it is treated without any risk of contamination. However, when the intervention relates to the actual arm and as is frequently the case, the disconnection of the toggle joint - gripper assembly makes it possible to leave these contaminated parts on a support within the cell whereas the slave arm, protected by its sleeve, is removed on the master arm side using a process well known in the art.
In the presently existing installations having such a disconnectable coupling device by which the toggle joint is fixed to the end of the slave arm, said device is a bayonet device making it necessary to rotate with respect to the arm, a ring carried by the toggle joint, the direction being a function of whether connection or disconnection thereof is to take place.
Although this device functions satisfactorily, it has the disadvantage of requiring the presence of a second manipulator or at least one motor member, such as a jack within the cell, in order to control the rotation of the toggle joint. This is not satisfactory, because it is obvious that the presence of this second manipulator is highly prejudicial with regards to the costs and overall dimensions of the cell. In addition, recourse to a back-up motor means such as a jack is not satisfactory, because it increases the risk connected with intervening within the cell for repairing a defective part. Moreover, if the motor means fails, it is not possible for the operator to connect or disconnect the coupling device. It also increases the number of passages through the cell wall necessary for controlling the motor means from the outside, which is prejudicial from the confinement and cost standpoints.